<template>
  <div>
    <button @click="isShow=true">点我弹个窗</button>
    <teleport to="body">
      <div v-if="isShow" class="mask">
        <div class="dialog">
          <h3>我是一个弹窗</h3>
          <h4>一些内容</h4>
          <h4>一些内容</h4>
          <h4>一些内容</h4>
          <button @click="isShow=false">关闭弹窗</button>
        </div>
      </div>
    </teleport>
  </div>
</template>

<script>
import {ref} from 'vue'
export default {
  name: 'Dialog',
  setup(){
    let isShow = ref(false)
    return {isShow}
  }
}
</script>

<style>
  .mask {
    position: absolute;
    top:0;bottom:0;left:0;right:0;
    background-color: rgba(0,0,0,.5);
  }
  .dialog{
    position: absolute;
    top:50%;
    left:50%;
    transform: translate(-50%,-50%);
    text-align:center;
    width: 300px;
    height: 300px;
    background-color: green;
  }
</style>